Electromagnetic relay



July [28 1953 R. D. JEssz-:E 2,647,185

ELECTROMAGNETIC `RELAY Filed Sept. 29, 1950 l2 Sheets-Sh'eet 2 WITNESSES: INVENTOR dw/,Vf Ralph D.Jessee.

BY y@ mw- ATTORNEY Patented .uy 28, Q

UNITED STATES PATENT vOFFICE ELECTROMAGNETIC RELAY Ralph D.y Jessee, Lima, Ohio, assigner to Westinghouse yElectric Corporation, East Pittsburgh, Pa., a corporation'of Pennsylvania Application September 29, 1950, Serial No. 187,571

7 Claims. (Cl. 200-98) My invention relates, gener-ally, to electromagnetic relays and, more particularly to relays of a latched type suitable for utilization in electrical power systems for aircraft.

An object of my invention is to simplify and improve the structure and the operation of a relay of the type described in the copending application ofB. O. Austin, Serial No. 179,054, led August 12, 1950.

A more specific object of my invention is to provide an electromagnetic relay of thelatched type which does not require close manufacturing tolerances.

Another object of my invention is to 'provide for readily adjusting the latching mechanism of a relay of the latched type.

A further object of my invention is to provide for mechanically latching the contact'members of a relay in the closed position.

Other objects of my invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with my invention, the contact members of a relay are retained closed by a latching mechanism which is released by the energization of a trip coil on the relay. They armature member for the trip coil is so mounted on the armature member for a reset coil that the trip armature may be actuated by the reset armature to actuate a contact lever which carries the m-ov- I',

able contact members of the relay. The trip armature, the reset armature, the contact lever, and the latching members are so disposed that the relay is mechanically and electrically tripfree.

For a better understanding of the nature and objects of the invention, reference may be had to the following detailed description, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a view, in plan, oi a relay embodying the principal features of the invention, portions of the relay structure being broken away for clearness;

Fig. 2 is a View, in side elevation, of the relay shown in Fig. 1;

Fig. 3 is a View, in section, taken along the line III-III in Fig. 2;

Fig. 4 is a View, in end elevation, of the relay, and

Figs. 5, 6, 7 and 8 are diagrammatic views showing different steps in the operation of the relay.

Referring to the drawings, and particularly to Figs. l to 4, the electromagnetic relay shown therein comprises an insulating base I0, a trip coil assembly I I, a reset coil assembly I2, a contact lever I3, a latch member I4 and an arc box assembly I5. The trip coil assembly II comp-rises a coil IB which is mounted in a U-shaped frame l and surrounds a core I8. The core I3 may be attached to the frame Il by a screw I9. The frame I'l may be mo-unted on a U-shaped memberZI whichmay be attached 'to the base I3 by rivets l22. An armature 23 is pivotally mounted cn an armature 24for the reset coil assembly I2.

The reset coil assembly I2 comprises a coil 25 which is mounted in a U-shaped frame 26 and surrounds a core 2l. The frame 26 may be attached-to the base Ill by L-shaped brackets 28 which are attached to the base by screws 2S. The armature24 is hinged to the brackets 28 by a hinge member 3|, which is attached to the armature 24 by screws 32, and a pin 33 which extends through the brackets 28. The core 21 may be attached to the-frame 25 by a screw 34. As explained hereinbefore, the reset armature 24 supports the trip armature 23.

As shown most clearly in Fig. l, the two armatures are so internotched that the armature 23 is vfree to rock on the armature 24, but cannot move longitudinally on the armature 24. The armature 23 may be `retained on the armature 24 by cotter keys 35 which are inserted through the armature 24. The two armatures are interconnected by a spring 36.

As shown most clearly in Figs. 2 and 3, the contact lever I3 may be of the shape of a cross which is hinged at its lower end to the brackets 2B by a hinge member 31 and a pin 38 which extends f through the brackets 28. The hinge member 3l may be attached to the contact lever I3 by screws 33. The contact lever I3 carries three movable contact members 4I each of which is disposed to engage a iixed contact member 42 mounted in the arc box I5.

Each contact member 4I is slidably disposed in an insulating bushing 43 in the contact lever I3. A spring 44 surrounds a portion of the shaft oi each contact member 4I and is so disposed between the arc box I5 and a washer 45 which engages the bushing 43 that the contact lever I3 is biased away from the arc box I5 by the spring 44. A spring 43 is mounted on each contact member 4I inside of the spring 44, and is so disposed between a shoulder 4l on the shaft of the contact member 4I and the washer 45 that over-travel of the contact lever I3 is permitted after the contact member 4I engages the contact member 42 when the contact lever is actuated toward the arc box I5 in a manner which will be explained hereinafter. A terminal 48 may be connected to the shaft of each contact member 4I between nuts 49 and 5I which are threaded on the shaft of the contact member.

The arc box assembly I5 in which the fixed contact members 42 are mounted may be of the usual construction. As shown most clearly in Fig. l, it has three compartments, one for each pair of contact members 4I and 42. Each compartment is formed by side sheets 52 disposed between opposite poles of magnets 53. Spacing A members 54 may be provided between the side sheets 52 and the assembly may be held together by bolts 55 which pass through plates 56 on the sides of the assembly at the lower portion thereof, and bolts 51 which extend through the side plates 52.

The entire arc box assembly may be attached to the base Il) by screws 58. Electrical connections may be secured to the contact members 42 by nuts 59. As shown in Figs. 1 and 2, brace members 6I extend from the arc box I5 to a U- shaped bracket 62 which is secured to the frame 26 of the reset coil assembly I2. The brace members 6I may be attached to the bracket 62 by screws 60.

The latch member I4 is pivotally mounted in the bracket 62 on a pin 63 which extends through the sides of the bracket 62. As shown in Fig. 2, one end of the latch I4 is biased upwardly by a spring 64. The upward movement of the one end of the latch I4 is limited by a tab 65 which is attached to the frame 26 by rivets 66. As shown, a portion of the tab 65 is disposed at an angle to the frame 26 and may be bent upwardly or downwardly to adjust the movement of the latch i4. A pad 61 is secured to the underside of the trip armature 23 and is disposed to be engaged by the latch I4 under certain conditions as will be described more fully hereinafter.

As shown most clearly in Fig. 1, portions 68 of the brace members 6I are bent inwardly to form stop members for the contact lever I3 to limit its travel away from the arc box I5 when the contact lever is disengaged from the armature 23.

As shown most clearly in Fig. 2, the reset armature 24 is biased away from the core 21 by a spring 1I which is connected between a bracket 12 attached to the base I6 and a bracket 13 attached to the armature 24. An adjustable tab 14 is attached to the frame I1 to limit the movement of the reset armature 24 away from the frame 26.

The reset armature 24 may be manually actuated toward the frame 26 and the core 21 by a rod 15 which is slidably disposed in brackets 16 attached to one leg of the bracket 2 I. One end of the rod 15 is bent inwardly at 11 to engage the armature 24. The other end of the rod may extend through a relay cover (not shown) to be accessible from outside the cover. A spring 18 may be disposed on the rod 15 between one bracket 16 and a washer 19 to bias the rod outwardly when it is released.

The operation of the relay may be understood by referring to Figs. 5 to 8, inclusive. In Fig. 5, the trip armature 23 and the reset armature 24 are shown in the positions assumed when the trip coil I6 and the reset coil 25 are deenergized. The contact lever I3-is shown in the position in which the contact members 4I and 42 are disengaged. The latch I4 is held down by the trip armature 23 which is biased by the spring 36.

In Fig. 6, the trip armature 23 is shown in the position assumed when the trip coil I6 is energized. The reset armature 24 is shown in the position assumed when the reset coil 25 is deenergized. It will be seen that the end of the trip armature 23 is disengaged from the contact lever I3. However, the movement of the contact lever I3 is limited by the stop member 68, thereby preventing the contact lever I3 from assuming a position in which it cannot be reengaged by the end of the trip armature 23. The relay may be reset by energizing the reset coil 25, provided the trip coil I6 is deenergized to permit the end oi the trip armature 23 to engage the contact lever I3.

As shown in Fig. '1, when the trip coil I6 is deenergized, the end of the trip armature 23 engages the contact lever I3. When the reset coil 25 is energized, the reset armature 24 actuates the trip armature 23 in a direction to actuate the Contact lever I3 to close the contact members 4I and 42. As also shown in Fig. 7, the latch I4 engages the pad 61 on the trip armature 23 to retain the contact members 4I and 42 closed so long as the trip coil I6 is deenergized. Thus, it is not necessary for the reset coil 25 to remain energized to hold the Contact members 4I and 42 closed. Accordingly, the reset coil 25 may be deenergized after the relay has once been reset. As explained hereinbefore, the relay may be reset manually by means of the rod 15.

As shown in Fig. 8, it is impossible to reset the relay either electrically or manually when the trip armature 23 is closed either electrically by the energizaticn of the trip coil I6, or manually by holding the trip armature in the closed position. When the trip armature 23 is closed the end of the armature is disengaged from the contact lever I3 and the contact members 4I and 42 cannot be closed.

Furthermore, the latch I4 cannot engage the pad 61 since the upward movement of the latch caused by the spring 64 is limited by the stop 65. Thus, the relay will assume the position shown in Fig. 5 when the trip coil I6 and the reset coil 25 are deenergized. If the reset coil only is deenergized and the trip coil I6 remains energized, the relay assumes the position shown in Fig. 6. Therefore, the relay is both electrically and mechanically trip-free since the contact members cannot be held closed either electrically or mechanically while the trip coil I6 is energized.

From the foregoing description it is apparent that I have provided a simplified and improved relay of the latched type in which the contact members of the relay are held closed by the latching mechanism, but are immediately released upon the energization of the trip coil of the relay. The relay is provided with a tripfree resetting mechanism which may be operated either electrically from a remote position, or manually by means of an operating rod or lever. The relay is relatively simple in construction and does not require close manufacturing tolerances since simple adjusting means are provided for making the necessary adjustments for securing the desired operation of the relay.

Since numerous changes may be made in the above-described construction and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

,1. An electromagnetic relay comprising a movable contact lever carrying contacts adapted to engage stationary contacts, a iirst movable armature member, a first coil adapted to actuate said rst armature member, a second armature member movably mounted on the first armature member, means for biasing said second armature member to a position to engage the contact lever to move the contact lever when the rst armature member is actuated by energization of said rst coil, and a second coil adapted to actuate the second armature member to a position free of the contact lever.

2. An electromagnetic relay comprising a movable contact lever carrying contacts adapted to engage stationary contacts, a iirst movable armature member, a first coil adapted to actuate said rst armature member, a second armature member movably mounted on the first armature member, means for biasing said second armature member to a position to engage the contact lever to move the lever when the `first armature member is actuated by energization of said first coil, latch means for retaining the second armature member in engagement with the contact lever, and a second coil adapted to actuate the second armature member to a position free of the contact lever and the latch means.

3. An electromagnetic relay comprising a movable contact lever carrying contacts adapted to engage stationary contacts, a irst armature member pivotally mounted for movement toward and away from the contact lever, a rst coil adapted to actuate said first armature member, a second armature member pivotally mounted on the rst armature member, means for biasing said second armature member to a position to engage the contact lever to move the lever when the first armature member is moved toward the contact lever by energization of the iirst coil, and a second coil adapted to actuate the second armature member to a position free of the contact lever.

4. An electromagnetic relay comprising a movable contact lever carrying contacts adapted to engage stationary contacts, a first armature member pivotally mounted for movement toward and away from the contact lever, a rst coil adapted to actuate said rst armature member, a second armature member pivotally mounted on the first armature member, means for biasing said second 4 armature member to a position to engage the contact lever to move the lever when the rst armature member is moved toward the contact lever by energization of the iirst coil, a latch member disposed to engage the second armature member to hold it in engagement with the contact lever, and a second coil adapted to actuate the second armature member to a position free of the contact lever and the latch member.

5. An electromagnetic relay comprising a movable contact lever carrying contacts adapted to engage stationary contacts, a pivotally mounted first armature member extending generally parallel to the contact lever, a first coil adapted to actuate said first armature member toward the contact lever, a second armature member pivotally mounted on the first armature member, means for biasing said second armature member to a position to engage the contact lever to move the contacts thereon into engagement with the stationary contacts when the iirst coil is energized to actuate the first armature member, and a second coil adapted to actuate the second armature member to a position free of the contact lever.

6. An electromagnetic relay comprising a movable contact lever carrying contacts adapted to engage stationary contacts, a pivotally mounted first armature member extending generally parallel to the contact lever, a first coil adapted to actuate said first armature member toward the contact lever, a second armature member pivotally mounted on the first armature member, means for biasing said second armature member to a position to engage the contact lever to move the contacts thereon into engagement with the stationary contacts when the first coil is energized to actuate the rst armature member, a latch member disposed to engage the second armature member to hold it in engagement with the contact lever, and a second coil adapted to actuate the second armature member to a position free of the latch member and the contact lever.

'7. An electromagnetic relay comprising a movable contact lever carrying contacts adapted to engage stationary contacts, a pivctally mounted first armature member extending generally parallel to the contact lever, a rst coil adapted to actuate said rst armature member toward the contact lever, manual means for actuating the first armature member toward the contact lever, a second armature member p-ivotally mounted on the iii-st armature member, means for biasing said second armature member to a position to engage the contact lever to move the contacts thereon into engagement with the stationary contacts when the irst armature is actuated toward the contact lever, a latch member disposed to engage the second armature member to hold it in engagement With the contact lever, and a second coil adapted to actuate the second armature member to a position free of the latch member and the contact lever.

RALPH D. JESSEE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,016,482 Cunningham Feb. 6, 1912 1,080,493 Smith Dec. 2, 1913 1,149,150 Steen Aug. 3, 1915 1,159,936 Harris Nov. 9, 1915 1,498,424 Christopher June 17, 1924 1,498,818 Smith June 24, 1924 1,749,602 Peterson Mar. 4, 1930 

